Grinding tool with eccentric rotation shaft

Abstract

A grinding tool with an eccentric rotation shaft of a grinding disc with attached grinding material installed via a bearing at a position that is shifted from the central drive shaft line of a rotating disc fixed on a drive shaft, comprises a clutch in which a grinding disc-side clutch component member installed on the grinding disc or on the eccentric rotation shaft that is fixed to the grinding disc and a rotating disc-side clutch component member installed on the rotating disc are linked via a sliding surface capable of sliding and of transmitting the drive force. The rotation rate of the grinding disc is limited to a stable range of rotation rates, preventing extreme elevation in the rotation rate and extreme reduction in the rotation rate; the workpiece is ground efficiently; and the tool does not generate marks or patterns on the ground surface.

The invention claimed is: 
     
       1. A grinding tool comprising:
 a motor having a drive shaft connected thereto; 
 a rotary disc fixed to the drive shaft defining an axis of rotation for the rotary disc; and 
 a grinding disc to which an abrasive member is attached, the grinding disc including: 
 an eccentric rotation shaft defining an axis of rotation of the grinding disc, the eccentric rotation shaft being attached through a bearing to the rotary disc at a position that is eccentric with respect to an axis of the drive shaft; and 
 a clutch including a grinding-disc-side clutch member and a rotary-disc-side clutch member that are connected to each other along a sliding surface that is capable of sliding and capable of transmitting a driving force, the grinding-disc-side clutch member being attached to the grinding disc or to the eccentric rotation shaft fixed to the grinding disc, the rotary-disc-side clutch member being attached to the rotary disc. 
 
     
     
       2. The grinding tool according to  claim 1 , wherein the sliding surface includes at least a set of conical shapes. 
     
     
       3. The grinding tool according to  claim 1  or  2 , wherein one of the clutch members is made of a plastic material and the other clutch member is made of a metal material. 
     
     
       4. The grinding tool according to  claim 3 , wherein the plastic material is a plastic material selected from a fluorocarbon resin, PEEK (polyether ether ketone), and a polyamide-imide, or a fiber reinforcement of the selected material.